Absence of Hydrocephalus in Spite of Impaired Cerebrospinal Fluid Absorption and Severe Intracranial Hypertension

Zusammenfassung

In the paper we have described four patients presenting papilledema, increased pressure and reduced CSF absorption, either caused by spinal tumours, leptomeningeal carcinomatosis or chronic encephalitis. All the patients had a normal CT-scan without any signs of hydrocephalus. The patients had their intracranial pressure (ICP) monitored for at least 24 hours, and they had a mean ICP of 30–35 mm Hg, recurrent plateau waves and a very high occurrence of B-waves. Resistance to CSF outflow (conductance) studied by a constant perfusion test was severely increased from 40–100 mm Hg/ml/min (normal R_out more than 8.3 mm Hg/ml/min). Despite the findings of severe increased intraventricular pressure no hydrocephalus was seen on serial CT-scans. Based on our investigations we must conclude that it was impossible to give any reliable pathophysiological explanation for the absence of the ventricular dilatation. A hypothetical, rate individual variation of brain resistance independent of the actual disease could account for this syndrome.